Incandescent electric lamp or the like and means for manufacturing same



.Jan. 29, 1935.

Y. SAKAKURA 1,989,292

INCANDESCENT ELECTRI C LAMP OR THE LIKE AND MEANS FOR MANUFACTURING SAME Filed Jan. 3, 1933 lizwe/abr ylizzzwia' 5 4.

Patented .Fan. 29, 1935 'INGANDESCEN'E EEIECTPUIC Him @Et rm LIKE AND MEANS FOR ip-"m.

seam I Yukitoshi Sakakura, Shi

ear :1;

r entree buya Kn, Tokyo, Japan,

assignor' to Toden Denhyu Kabushiki Kwaisha...

Tokyo, Japan Application .ianuary 3, 1933, Serial No. 649,835

. Japan August 2 3., 1932 ll Claim.

This invention relates in general to improvements in incandescent lamps or the like and has more particular reference to the-sealing of the I exhaust tube within the recess of the stem tube. 5 In the usual tip-less incandescent electric lamp, the sealed end or the tip of the exhaust tube which is attached in the recess of thestem tube, projects outside the stem tube, so that very often the lamp is damaged during the subsequent prol0 cedure of manufacturing after the bulb has been exhausted and sealed. It hinders the attachment of the base owing to the projection of the sealed end or the tip of the exhaust tube outside ,the recess of the stem tube. Especially it is not adapted to place another thing in the recess of the stem tube of the incandescent lamp of this kind as for example in my prior U. S. Patent No. 1,802,838 dated Apr. 28, 1931, which is provided withanother smaller incandescent lampin the recess of the stem tube of the outer lamp. In the manufacture of the outer lamp in my said patent it has hitherto been proposed to make, by application of heat, a hole on the brim of the junction of the stem tube to the bulb, and then an exhaust tube is attached thereon by application of heat, which manipulation is very difiicult and troublesome.

To overcome the above difiiculties, it is proposed in accordance with the present invention to provide an incandescent lamp wherein the sealed end or the tip of the exhaust tube is completely protected within the recess of the stem, and further for this purpose to provide means whereby the sealing of the exhaust tube may'be easily carried out at inside of the recess of the stem tube. ,Further objects, purposes and characteristic features will appear as the description progresses, reference being made to the accompanying drawing, in which- 40 Fig. 1 is a longitudinal sectional view showing the state of sealing the exhaust tube in accordance with the present invention.

Fig. 2 is a longitudinal sectional view of the, improved incandescent lamp manufactured according to Fig. 1.

fl'hroughout the drawing, (1) designates the lamp bulb, (2) the stem tube, (3) the brim of junction of the stemtube to the'bulb, and (a) the exhaust tube. I

Referring now to Fig. 1, which shows the state of sealing the exhaust tube (4) near its root in the recess of the stem tube (2) according to the present invention, a device comprising an oxygen pipe (12) supported along an ordinary forked gas burner (7) by the handle (10) and extending its opening (13) near the forked head (8) of the gas burner, is prepared.

The head of the burner is put into the recess of the stem tube (2) and the flame is applied on the exhaust tube (4) near its root as shown in Fig. 1. The flame will continue to burn in the confined recess of the stem tube, owing to the sufficient supply of oxygen, and the exhaust tube, may be sealed leaving possibly a short tip at the bottom part of the stem tube recess, as shown in Fig. 2. Oxygen and fuel gas are properly adjusted. to maintain correct combustion according to circumstances.

Fig. 2 shows an incandescent'lamp embodying the present invention, with its exhaust tube sealed by the means shown in Fig.4. According to the present invention the sealed end or the tip of the exhaust tube (4) is completely protected within the recess of the stem tube (2) so that any damage owing to projecting of the sealed tip of the exhaust tube during the subsequent procedure of manufacturing incandescent lamp is entirely avoided. A smaller lamp may be fully admitted within the recess of the stem tube as applied to my prior U. S. Patent No. 1,802,838.

Having now particularly described and ascertained the nature of my saidinvention and in what manner the same is to be performed I declare that what I claim is:-

As a new article of manufacture an incandescent electric lamp or the like having an exhaust' tube attached at the bottom of the stem of said stem, whereby the sealed tip of the exhaust tube is entirely protected within the recess of the stem tube, said lamp being further adapted to receive another smaller incandescent lamp in the recess of the stem tube. 1

YUKITOSHI SAKAKURA. 

